Fix unused private field warning.

Summary: The member is private and unused if HAVE_LIBCOMPRESSION is undefined, which triggers Clang's -Wunused-private-field warning.

Subscribers: lldb-commits

Differential Revision: https://reviews.llvm.org/D56458

git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@350675 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed